


when

by i_like_stars



Category: Haikyuu!!
Genre: Angst, Disease, F/F, Fluff, Fluff and Angst, Happy Ending, I Wrote This Instead of Sleeping, I might add more more tags, I wrote this just for fun, M/M, Mentions of kagehina, slight kiyoyachi, this au popped in my head at 3am and here iam
Language: English
Status: In-Progress
Published: 2021-03-18
Updated: 2021-03-19
Packaged: 2021-03-26 03:14:47
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 4,376
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/30099453
Author URL: https://archiveofourown.org/users/i_like_stars/pseuds/i_like_stars
Summary: A immortal AU where Tsukki doesn't die but Yams does.(Based on thistweet!)*Updates on Sundays*
Relationships: Tsukishima Kei/Yamaguchi Tadashi
Comments: 4
Kudos: 10





	1. death

**Author's Note:**

> Hi ^^

**Summary for the Chapter:**

> tadashi dies and kei is mourning over his lover's death

Kei stood in front of his lover's grave, sobbing. This was what Kei absolutely hated about him being an immortal, every time he would see Tadashi eventually die and him just staying alive waiting for his lover to be reborn. This death was the second time Tadashi disappeared from the world.

Kei placed the flowers on his hand on Tadashi's gloomy grave. He then silently walked back to his car and placed his head on the steering wheel.

He looked back at the grave and sighed. "I'll look for you again, I promise."

Kei started the car and went back to his now lonely apartment.

_"Really, Tsukki? You're an immortal being?" Tadashi tilted his head, confused at what the blonde was saying._

_"Yes and...I- it's not like I don't want to date you it's just- I'd lose you!" Kei sputtered._

_Tadashi forced out a fake laugh. "Y'know Tsukki, you don't have to come up with a reason to say you don't like me. You should have just told me you don't like me!"_

_"I’m not lying! This curse is-"_

_"It's really okay, we could just forget all of this and still become friends-"_

_Kei suddenly pulled Tadashi into a sweet kiss. Tadashi squeaked in surprise but kissed back._

_The blonde pulled away to see Tadashi's eyes dripping small crystal clear tears. Kei smiled and wiped them away, he pressed a soft kiss to Tadashi's forehead._

_"I love you...so much." Kei murmured hugging the freckled boy in his arms._

_Tadashi quietly cried, a small relieved smile on his lips. "I really thought you didn't Tsukki..."_

_After a moment, Kei sighed. "You know...when I date and marry you, you'll die but I won't right?"_

_Tadashi looked up, eyes a bit puffy but he still managed to look cute. "You're actually an immortal?"_

_"Do I look like the type to lie about that type of subject?"_

_"Well- fair enough." Yamaguchi paused for a bit. "Does that mean you'll see me die over and over again?"_

_Kei nodded a hint of pain in his eyes. "And I don't know if you would be reborn again, I can't live without you."_

_Tadashi looked like he was about to cry again. "Then...isn't there some way to undo you being immortal..?"_

_"I...don't know…"_

_Tadashi looked up at his boyfriend with eyes tearing up but determined. "I know at some point we'll know how to undo your curse."_

_Kei hugged the latter, quietly crying. Tadashi hugged back._

_"If I ever die, Tsukki...I'll find you again and again and again until we lift your curse."_

_Kei sniffed and smiled at the freckled boy. "Okay."_

Kei woke up, remembering his dream about how he told Tadashi about his painful secret. His eyes drifted to the empty, cold spot beside him. Kei's eyes glazed with unshed tears. He knew Tadashi and him were going to meet again- but God, it hurt so badly.

He sat up and tried to make a healthy breakfast but all he saw was a pack of French fries in the freezer that Tadashi loved to cook every time they have a Movie Night.

He shut the fridge and walked to the counter, picking up Tadashi's favorite cereal. He sighed; he couldn't escape the fact that everything reminded him of Tadashi.

"I miss you…so much, Tadashi..." He whispered, voice shaking. "...I don't know if I could wait another more 20 years to meet you."

He placed his head on his pale hands and sobbed. "Why do I have this curse anyway?!" He shouted, tears pouring down from his eyes.

_I miss you so much._


	2. reunion

**Summary for the Chapter:**

> it's time for kei to meet his lover again but there is something wrong

Kei walked to his favorite café, keys jingling in his pocket. It was 25 years since Tadashi’s second death; Kei would’ve been lying if he said that he wasn’t ecstatic to meet his lover once again after all those years.

He pushed open the café door and stepped inside. He walked up to the counter and his eyes widened and his smile went brighter. There standing, was his one and only. With his beautiful freckles, bright smile and his hair tied up into a ponytail.

“Tadashi!” Kei happily ran up to his lover.

The latter turned his head and watched as the blonde run up to him.

“Tadashi, there you are! I waited for yo-“

“Excuse me do I know you?” Tadashi asked Kei in a polite manner.

Kei’s world crumbled to pieces. _Huh?_ He stood there dumbstruck in front of a nervous Tadashi.

“Wait- you don’t know me? But didn’t you remember right away on your second life?”

Tadashi shrank under the blonde’s gaze. “Uh- you must be mistaking me for someone else…” He muttered.

Kei gulped. This wasn’t what he expected; when Tadashi died the first time and was reborn the first time he kept all his past life memories.

“…Ah…okay, you must not be the one I’m looking for.” Kei whispered in a quavering voice.

Tadashi looked at the miserable stranger; he tried to comfort the blonde by offering to buy him a cup of coffee. Kei looked at his lover with sad eyes but he smiled and nodded.

_Tadashi WHAT were you thinking??? Inviting a stranger that says he waited for you and talks about reincarnation into your APARTMENT???_ Tadashi screamed at himself, Kei walking beside him.

Kei was still the same, miserable and had a downcast vibe. He was staring into space whilst Tadashi was overthinking and regretting that he invited a stranger to his apartment, and the worst part was that Tadashi didn’t have any roommates. He looked at the unhappy man beside him.

 _He doesn’t look that bad, maybe he lost someone._ He pondered accidentally staring too long at Kei.

The blonde glanced at his lover and made eye contact with him; he blushed and looked away from the freckled man. _Shit, why is he so cute?_

Tadashi scratched his cheek and continued on walking. He noticed his apartment was near and he took his keys out of his coat pocket.

The pair approached the house and Tadashi inserted the key and opened it, inviting Kei to his quiet house. The blonde silently followed the latter to his living room.

“Do you want water?” Tadashi asked Kei who was sitting on his couch.

“Oh yes, thank you.” Kei looked up and was met with a soft smile. Kei’s heart ached. If it wasn’t for Tadashi losing his past memories then he would’ve been cuddling and giving him kisses right now.

Tadashi plopped down on a seat across Kei with two glasses of water, interrupting the blonde’s thoughts. The two sat there, sipping their water in silence.

“So uh, what was that reincarnation stuff?” Tadashi giggled nervously.

“That was…nothing…I mistook you for someone else.”

“Oh! Well, I could help you find that person- if you’re waiting or trying to find them!”

Kei looked up and saw Tadashi giving him a caring look. _He’s still as friendly and caring as ever._

“If that’s okay with you.” Kei replied. Kei wanted to make this an excuse to hang out with Tadashi, he knew this was probably low of him but he didn’t know how to restore Tadashi’s memories.

Tadashi and Kei spent the next few hours trying to find if there was another person who looked like the freckled man, but they had no information even after hours of stalking accounts named “Tadashi”. Kei felt bad that he was faking but the last few hours he got to see Tadashi smile and laugh at his lame jokes just like before. His chest was filled with an indescribable warmth he felt only around Tadashi.

Eventually they gave up and the freckled man started warming up to the blonde, they even exchanged numbers.

The pair was lying on the carpeted floor, Tadashi’s laptop open next to them. Tadashi turned his head to face Kei and asked, “So…Kei…I found out there is going to be a firework show tonight, and uh- my friends can’t come so maybe we could…y’know see it together?”

Kei turned his body and he was now facing Tadashi. “Sure, why not?”

“It’s a promise then.” Tadashi smiled as he closed his eyes. Kei stared at him until he heard soft snoring. The blonde smiled and sat up; he closed the laptop and lifted Tadashi’s body on the couch. He then picked up a nearby futon and draped it over Tadashi; he also added a soft pillow for he knew Tadashi has a habit of cuddling anything in his sleep.

Kei sat on the floor, staring at Tadashi’s peaceful sleeping face. He reached out to brush some hair strands out of Tadashi’s face and sighed. He wanted to kiss him so much, but he didn’t want to be labeled as some weirdo who said weird things and wanted to kiss a supposed friend.

He sighed again and laid on the carpeted floor, he wasn’t comfortable but he would do anything to make his Tadashi cozier. He slowly began to fall into a deep sleep, not noticing a group of people coming inside Tadashi’s supposedly lonely apartment.


	3. friends

**Summary for the Chapter:**

> kei meets tadashi's friends

Kei woke up to the sound of people arguing, he noticed Tadashi was part of the argument.

“He’s not a bad guy! He just needs help on finding someone!”

“Seriously, Yamaguchi you’re too nice.” A low voice sighed.

“Yeah…we don’t want you hurt.” A small female voice agreed.

“Yamaguchi, what was he like?” After that, Kei saw a blurry orange thing.

He rubbed his eyes and saw a small man with fluffy orange hair, the orange-haired man squeaked and backed away hiding behind a black haired man.

Kei sat up and saw a group of people in the kitchen, one of them was Tadashi.

“Kei! Ah- sorry these are my friends, they can be overprotective-“ Tadashi began.

“WE ARE NOT!” The black haired man barked causing the small blonde lady jump.

Tadashi sighed, exasperated. He quickly appeared on Kei’s side. “You guys can judge Tsukki but I’m still helping him!” he huffed.

The whole room went silent and everybody stared at Tadashi. The freckled man shrank under the weight of his friends’ gazes. Kei’s eyebrows rose hearing his old nickname. But he coughed and tried to act innocent so his cover won’t be blown.

“‘Tsukki?’” Kei asked the blushing man. “Is that a nickname?”

Tadashi blushed harder. “W-well maybe but- just- don’t mind it…” He trailed off.

Kei looked at Tadashi’s group of friends. He noticed that the short man was still hiding behind the threatening black haired man. The small blonde was off to the side, and all of them were staring at Tadashi.

“Waahhh! How come you gave him a nickname but not me?” The short man whined.

“J-just don’t mind that okay?!” Tadashi pouted. “A-anyways…you guys should introduce yourselves to Kei.”

“…Fine. I’m Kageyama Tobio.” The black haired man grumbled. Kei didn’t like this grumpy man at all.

“Hinata Shoyo!” The one with the fluffy orange hair said energetically. Kei cringed. He definitely didn’t like the man named Hinata, too much energy.

“Uhm- Y-Yachi Hitoka…” The small blonde muttered shyly. Kei was fine with her but he thought that she definitely is the type to be so shy and nervous that she’ll throw up just from ordering at McDonalds.

“I’m Tsukishima Kei.” The blonde replied to the group.

Tadashi smiled, glad that his friends were getting along at least a little bit. Kei felt butterflies in his stomach, he already saw the smile like- 10 times that day but he just can’t seem to stop flushing when his lover did cute things.

“Oh right! We still have to go to the Fireworks Show this night!” Tadashi beamed, helping Kei to stand up.

Tadashi then pulled Kei towards his kitchen table, surprising Kei and the others.

“Don’t tell me you invited this complete stranger-“ Kageyama snapped.

“Kageyama!” Tadashi hissed.

Kageyama pouted and was hugged by Hinata. Kei then realized that these complete opposites were probably dating.

Kei stood awkwardly and felt like he didn't fit in with Tadashi's friends. But Tadashi was determined to make his friends like his new companion. Tadashi sat down and made the others sit down on the dining seats.

"Oh right, are you guys coming?" Tadashi asked his friends. " Kei is coming, what about you four?"

"We actually went here to surprise you and we were supposed to go to the Fireworks!" Hinata piped up.

"But then 'Tsukki' came along." Kageyama sneered.

Kei glared at Kageyama, the black haired man suddenly received a slap on the head from his boyfriend.

"Yamaguchi told you to stop being mean remember?!" Hinata scolded Kageyama who was pouting.

Tadashi sighed. "Do you guys have yukatas?"

"Of course."

"Yeah!"

"I have one."

"That's great! How about you Yachi?" Tadashi turned to the small blonde.

"I have a kimono." She agreed.

"Then it's set!" Tadashi cheered. He looked at the time and saw that it was 2 hours before the show.

Tadashi led his friends and Kei outside. "I'll meet you guys at the park, if you guys arrive first then save a spot."

Kageyama, Hinata and Yachi nodded. Kei didn't want to leave Tadashi but he assured his self that he would meet him again. Kei and Tadashi watched as the group separated, Hinata and Kageyama on the left and Yachi on the right.

Kei gave a farewell to Tadashi, if he could he would've just gave Tadashi's hand a kiss.

He started walking away and to the café to order a small cup of coffee then walk back to his own apartment. He couldn't wait for the Firework Show.


	4. memories

**Summary for the Chapter:**

> tadashi remembers

**Notes for the Chapter:**

> wow fluff  
> (I made some edits about the spelling and some other stuff)

Kei stood, a red blanket lying on the soft grass beside him. He was the first one to arrive and he showed up wearing a blue yukata. He noticed a group made out of five people. He saw a green ahoge and knew it was his Tadashi.

He waved to the group of people and the one with the green ahoge came running towards him.

"Tsukki!" Tadashi sang.

Kei flinched at the nickname, but he regained his composure and waited until the whole group arrived.

"Tsukki, is this your saved spot?" Tadashi gestured to the red blanket lying on the grass.

Kei nodded and then noticed Tadashi had a bunch of bento boxes in his hand. "Do you need help with that?"

"Oh, this? I'll just set it on the blanket for now; I’m saving it until for the show." Tadashi then placed the bento boxes on the red blanket.

"Can we get takoyaki Kageyama?? Can we? Can we??" Hinata jumped up and down in his red yukata.

Kageyama grumbled something under his breath but agreed. And with that the couple went off to the takoyaki stall. Yachi, Tadashi and Kei were left on their spot. Kei glanced at Tadashi; he hadn't paid attention to what his lover was wearing.

Tadashi was wearing a dark blue yukata almost the same as Kei's, his hair was also tied up in a small ponytail. His freckles were... disappearing?

Kei was almost about to say something about it but then Yachi interrupted his train of thought.

"You guys can go take a walk; I'll just stay here and guard the bento boxes and our spot." Yachi told the pair. She sat down on the blanket and said, "I'll meet you guys here!"

Tadashi nodded and took Kei's hand, the other waving at Yachi. Kei wanted to ask why his freckles were faded; he wanted to ask why Tadashi used 'Tsukki' again. But he didn't want to ask it in public, Kei felt like he knew the reason for the disappearing freckles. Makeup.

"Tsukki! Look, look! They have fries!" Tadashi lit up at the sight of his favorite food.

Kei sighed and brushed off the two questions for now, for the time being, he would enjoy his alone time with his lover.

Kei realized it was almost time for the firework show. He and Tadashi ended up in a small clearing with trees surrounding them; they could hear the bustling crowd from that side of the park. Stars were twinkling beautifully above them. Kei figured this would be the time to get some answers from the earlier questions.

"Tadashi, why are you using makeup?" Kei bluntly asked.

Tadashi flinched. "What- what do you mean Tsukki?"

"I guess I was right." Kei touched the flushing man's cheek; he rubbed his freckles and revealed that he was wearing foundation.

Kei's heart throbbed. He knew Tadashi hated his freckles, on multiple occasions he caught him trying to hide it. Kei then felt something wet fall down Tadashi's freckled cheeks. Kei wiped the tears from Tadashi's cheeks and placed a kiss on his forehead.

"You're beautiful just the way you are, 'Dashi."

Tadashi hugged Kei tightly as a reply. A few moments after, Kei heard Tadashi mumble something.

"I think I've met you before, Tsukki. I’m not sure when..."

Kei's eyes widened. He cupped Tadashi's cheeks and kissed him on the lips, as if on cue, the fireworks began to design the starry night sky. Kei heard nothing but the steady breathing of his lover.

As their lips separated, Kei asked Tadashi one last question.

"Do you remember me?"

Tadashi bobbed his head and laughed. "I didn't know how but I just remembered everything."

Kei smiled lovingly at the man, he didn't know how or why his lover got his memories back but he was glad he did. He started to cry tears of joy at the sight of his lover.

"Aweee Kei, don't cry!" Tadashi giggled, still holding Kei's arms.

As they were having a reunion, the pair didn't realize 3 people were hiding in the bushes spying on them. Kei saw a familiar fluff of orange hair in a bush. He rubbed his eyes and unmistakably saw the one and only, Hinata Shoyo.

Kei cringed seeing that Kageyama and Yachi were there with him. Tadashi noticed Kei's changed of mood and looked behind him and his heart stopped. He quickly let go of Kei and stood a good one foot away from him.

Hinata then realized they were seen and stepped out of the bushes with a small Polaroid camera. "You've been caught!" He grinned widely.

Kageyama and Yachi soon followed after. Kageyama was smiling evilly for he had something to blackmail Kei with. Kei noticed this and started glaring back.

Yachi stepped in before a fight broke out. "You guys- let's just go back to our spot okay? Someone could steal the bento boxes!"

Hinata agreed hanging his camera around his neck. "I can't wait to taste the bento Yamaguchi made!"

Kageyama appeared beside him. "You literally just ate a lot of takoyaki."

"I’m still hungry!"

"Dumbass."

Kei and Tadashi followed last, holding hands as they walked out of the small clearing. As they finally got out of the clearing, the crowd was separated into groups, somewhere lying on blankets eating, some were still ordering food in the stalls and some were just standing with their loved ones looking at the fireworks.

As Yachi was walking, she saw a beautiful lady with black hair and a mole under her soft looking lips. She made eye contact with the beautiful woman and blushed. The black haired woman winked and smiled at her, which caused Yachi to malfunction and almost faint.

The group finally reached their blanket and saw that the bento boxes weren't stolen nor was their spot. The group sat down and Tadashi started to give away each bento to the four. The group peacefully ate whilst looking at the marvelous fireworks.

Kei held Tadashi's hand; Tadashi smiled and squeezed his hand as a reply.

"I love you, Kei." Tadashi said to him over the bang of the fireworks.

Kei kissed his lover's cheek, he never ever ever wanted to let go of Tadashi's hands ever again.

He almost forgot that he was immortal.

(Bonus):

"Oh wow the picture you took....it's actually kinda nice not gonna lie." Tadashi commented on the picture of the time they were caught in the clearing that Hinata took.

"I know right? It's like something out of a Ghibli movie!" Yachi agreed.

"Let me see that." Kageyama said as he grabbed the picture out of Hinata's hands. "Oh...that actually does kind of look nice, the fireworks were on cue too."

"Why did he cry Yamaguchi?" The three turned to Tadashi looking for answers.

Tadashi realized Kei didn't want his secret to be said so he blurted out the first thing that came to his mind.

"He told me he had a splinter..?"

"Well that's uninteresting." Hinata turned back to his camera.

"Loser." Kageyama sneered and gave the picture back.

"Come on guys be nice!" Yachi sighed.

Tadashi giggled. He was lucky to have met them in this lifetime, wonder if he would in the next?

**Notes for the Chapter:**

> Hooray two chapters! (I'll probs post two chapters again next Sunday cause I have WAY too much time in my hands)


	5. disease

**Summary for the Chapter:**

> tadashi's third death

**Notes for the Chapter:**

> wow angst

Kei sat next to a white hospital bed, Tadashi lying on it dazed. He turned his head to face Kei and scrunched up his nose. "Who are you?"

Kei gulped and forced a smile. "It's Kei. Your Tsukki, remember?"

Tadashi stared off to space. After a few silent moments, he nodded like he remembered who his lover was. "I remember."

Kei smiled and squeezed Tadashi's hand. He didn't even last twenty years with his lover. They lasted a good eleven years until Tadashi was diagnosed with a disease that made his memory fade bit by bit and unexpected pain in different parts of Tadashi's frail body. And apparently it was incurable and deadly.

_"Kei...I don't want to die." Tadashi sobbed, Kei rubbing circles on his back._

_Kei tried to stop his tears but failed, he cried silently in Tadashi's sweet smelling hair. The couple sat there on their bed, crying at the terrible news._

_"I can and will meet and find you again, Tadashi."_

"Tsukki, my head hurts..." Tadashi said in a pained voice.

Kei hated to see his love like this, helpless and in pain. He hated everything. He hated whoever put this curse on him. He hated he had to watch Tadashi die over and over again and for what? He sighed and reached out a fruit basket brought by Yachi.

"Maybe fruits would help you?" Kei asked the freckled man.

Tadashi nodded and watched as Kei slice an apple and skin it. Kei gave a part to Tadashi and one for his self. He watched as Tadashi weakly bite into the apple.

"Mmgh...too hard.." Tadashi groaned. He put the bitten apple on the plate Kei gave him and stared off to space again.

"Tsukki...why am I here?" He faced Kei with a pained expression.

"You...have a disease." Kei replied in a shaking voice.

Tadashi's eyes were dripping clear tears. "I don't want to die."

Kei hugged Tadashi and sobbed. "I know...I know...”

"Promise me Kei, we'll meet again right?"

"I promise."

"Hey... Tsukishima...are you okay?" Hinata tilted his head, seeing the miserable man's tired face.

"Yeah, you should sleep. We could take care of Tadashi." Yachi patted Kei's broad back.

Kei shook his head. He didn't want to leave Tadashi's side. He was afraid that if he wasn't there Tadashi would die the time he comes back.

Yachi and Hinata looked at Kei with sympathy. Kageyama then exited Tadashi's hospital room with puffy eyes.

"How is he?" Hinata asked his boyfriend.

"He isn’t doing well, he forgot about me. I tried to ask if he knew you and Yachi but he only knew Tsukishima over here." Kageyama replied, a hint of sorrow in his voice.

Yachi gasped, about to cry in front of the three boys. Hinata had a downcast look that was rare for a happy boy like him. Yachi silently sobbed at the fact that she will lose her dear friend, Hinata patting her back while looking like he was about to cry too.

Kei then stood up and rubbed his tired eyes. "You guys can rest, I'll stay with Tadashi."

Kageyama nodded. "Call us if anything happens."

And with that, Hinata and Kageyama guided the crying Yachi to the hospital exits. Kei entered Tadashi's room, on the white hospital bed, laid a weak looking Tadashi. Kei knew it was almost time to say farewell to his lover, the doctors said he could die anytime soon now.

"Mmh. Kei?" Tadashi looked at the tall blonde and smiled. "Hi."

Kei sat down on the chair next to Tadashi and squeezed his hand. "Are you okay?"

Tadashi squeezed Kei's hand back. "Yeah...why was there a black haired man in my room earlier?"

"You don't remember Kageyama?"

Tadashi paused for a second. "No...Is he someone I forgot? Should I remember him? Is it bad to not remember him?"

"No it's not bad... he's a friend of yours...Yachi and Hinata too."

"Oh I remember the black haired man mention Yachi and Hinata. Were they all my friends?"

Kei nodded, still holding Tadashi's weak hand.

"I see... Kei, I’m tired can I sleep?"

"Of course you can..."

Tadashi closed his eyes, his breathing steady. Kei smiled, he liked it when Tadashi breathes, for him, it's a sign Tadashi isn’t leaving too soon.

Kei kissed Tadashi's cheek. "Sleep well."

"Kei, everything hurts..." Tadashi whined, tears falling down from his eyes.

"It's okay; I'll get the doctors-"

Tadashi grabbed his lover's hand. "No...Stay...”

Kei didn't know what to do. If he got the doctors, Tadashi would be lonely, but if he stayed with his lover, Tadashi would die.

"It's okay, I’m going to die anyways..." Tadashi gave Kei a hopeful smile.

Kei couldn't stop his tears. He sat on the seat and held Tadashi's hand. The heart monitor was beeping irregularly and Tadashi's breathing became heavy.

"Hmm...Kei." Tadashi called out to the blonde.

"Yes?"

"I'll meet you again, and we'll be happy next lifetime okay?"

"Mhm. I promise. I'll come find you whatever country or planet or galaxy you are. I promise." Kei wiped his tears but they still wouldnt stop.

Tadashi sighed. "I'll meet you again, Kei."

Kei watched as his lover closed his eyes and he heard a long beep. He stood up and kissed Tadashi's forehead.

"Goodbye, my love. I'll meet you again."

**Notes for the Chapter:**

> Hello hello it's me again, hope you liked this chapter! (Also idk what disease I wrote about or if that disease even exists)

**Author's Note:**

> hope you like this fic! feedback is very appreciated! <3


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